The Owyhee River is a 346-mile-long tributary of the Snake River that begins in northern Nevada and flows through southwestern Idaho, before finishing its route in Oregon. The downstream section of the river below the confluence with the South Fork of the Owyhee River is known as the "Grand Canyon of the Owyhee," referring to the steep, rhyolite walls ranging in height from 250 feet to over 1,000 feet near the Oregon border. Floating the Owyhee is popular in the spring during higher water flows, and low water float trips are possible in smaller craft. The Owyhee River and its major tributaries are generally rated as Class II whitewater, although several Class IV through Class VI sections exist in the Lambert and Garat Gorges. The upper section, referred to as the East Fork of the Owyhee River, is recommended for only kayaks and whitewater canoes, as there are two difficult portages located seven and nine miles above the confluence with the South Fork. (rivers.gov) Use the Crutcher Crossing and Rome USGS gauges for water level. Boater guide https://www.blm.gov/sites/blm.gov/files/documents/files/Media-Center_Public-Room_Idaho_Bruneau-Jarbidge-Owyhee_BoaterGuide.pdf
rivers.gov